Frequently Asked Questions (English only)
Differential Pressure Sensors
Can I use your DP Sensors for liquids?
No, the SDP600, SDP1000 and SDP2000 series DP sensors are designed for non-corrosive gases.
Please refer to our product line of liquid flow sensors.
I get different readings when I compare your sensor with my reference using a membrane-based DP sensor. Is this normal?
It depends on the set-up. Due to the dynamic measurement principle, a small air flow is required. This air flow through the sensor creates a dependence on the tube length. The error is less than 1% with a tube length up to 1 m (with 3/16 inch inside diameter). For more details about this topic, see application note 'Pressure Drop In Hose Differential Pressure SDP6x0' in the Download Center.
Keep in mind that the SDP sensor does not depend on absolute pressure and temperature in the same way as a membrane sensor. The application note 'Selection Guide Differential Pressure Sensor SDP6x0' can help to understand the advantages of the dynamic measurement principle. Refer to the datasheet for the standard calibration conditions.
Can I use your DP sensors for gases other than air?
The sensor is calibrated for air. If used with other gases, the sensor's measurement results depends on the thermal properties of the gas compared with air. Note that this also applies to the zero point and temperature compensation.
Please avoid aggressive or etching substances, such as H2O2, NH3, etc.
Do you have conversion factors available if I want to use your DP sensor with gases other than air?
No, a conversion factor would in most cases not give acceptable results. For high volume applications, we are happy to discuss customized versions of our differential pressure sensors.
Are your differential pressure sensors suitable for HVAC applications?
Yes, they are suitable for a wide range of HVAC applications and we are rapidly gaining market share. For more details, see flyer 'DP Sensors for HVAC Applications' available from the DP sensor Download Center.
I need more than one DP sensor in my application. Can I have DP sensors with different I2C addresses?
No, all SDP500 and SDP600 series are produced with the same I2C Address. However, we are able to provide application notes for solutions using I2C multiplexers and how to change the I2C address yourself. Please send an email describing your requirements to firstname.lastname@example.org.
How can I test your SDP600 family sensors easily?
The Evaluation Kit EK-P3 is a cost-efficient solution for such tasks. The sensor can be connected to a PC/laptop via the I2C to USB converter, and the software with the kit allows the logging of data to a text file and includes graphical representation of DP values on screen.
Can I use your SDP611/SDP601 as a mass flow meter?
Yes, in theory this is possible to +/- 0.12 slm. However, the output will always be in differential pressure, which is proportional to the mass air flow through the sensor. It is also important to note that there will be a large inter-sensor variation when using the sensor directly as a flow sensor. This means that every sensor has to be recalibrated to find its individual differential pressure to mass air flow conversion curve, which is not linear. The good thing is that external temperature compensation is not required.
The SDP600 series sensor is most suitable for a mass flow measurement in a bypass configuration. For more details, please see 'Selection Guide for SDP600 Differential Pressure Sensors', which can be found in the Download Center.
For high volume applications, a customized calibration for flow can be considered. Contact email@example.com for more information.
What is the difference between SDP510/SDP610 and SDP511/SDP611?
The difference between the sensors is the temperature compensation. For a detailed description, please see 'Selection Guide for SDP600 Differential Pressure Sensors', which can be found in the Download Center.
Your datasheet states that the SDP500 series is calibrated in only one direction. I noticed that I also get an output signal in the opposite direction. Is this normal?
Yes, this is normal. But please be aware that sensor output for negative differential pressure is not calibrated.
The sensor output can be used to detect negative pressures, but does not accurately measure negative differential pressures. Use the SDP6xx when a fully bi-directional sensor is required.
SDP1xxx / SDP2xxx
I want to hand solder the SDP1000/SDP2000. Do you have temperature and time recommendations for the soldering process?
For manual soldering, we recommend soldering iron temperatures up to 350 °C and a soldering time of maximum 3 seconds.
Your evaluation kit EK-P3 comes with an SDP610 500Pa. Can I buy the kit with a different sensor?
The content of the kit is fixed, but the kit works with any SDP6xx or SDP5xx sensor. An additional sensor can be bought with the kit.